The present invention relates generally to a power generating mechanism for use in electronic apparatus and in particular to a power generating mechanism for generating power using heat generated by a heat generating component provided in an electronic apparatus such as a computer.
There has been a strong demand for a reduction in power consumption of electronic equipment due to environmental and ecological concerns. In addition, energy efficiency in terms of performance vs. power consumption is important to battery-driven portable equipment or the like, and is directly related to the amount of time available to operate the equipment. Thus, efforts are being made to further reduce power consumption. One way of doing this is to improve efficiency by reusing lost energy in equipment.
For example, notebook personal computers have a large amount of energy lost therefrom as heat because a semiconductor device therein such as a CPU or an electric circuit therein becomes hot. Further, many pieces of equipment include what is called a CPU cooler for preventing the CPU from malfunctioning due to heat, and excess power is consumed to drive a ventilation fan of the CPU cooler.
Techniques for generating power using heat generated by a heat generating component have been developed, as disclosed, for example, in U.S. Pat. No. 5,921,087. According to this patent, power is obtained by interposing a thermoelectric element using the Seebeck effect (the effect of generating power using heat), between a CPU and a diffusion cooling heat sink for the CPU, to change the temperature of the thermoelectric element.
This structure, however, has a thermal resistance between the CPU and the heat sink, thereby significantly reducing the effect of cooling the CPU. A structure for using a fan to cool a diffusion side of the heat sink has also been disclosed. In this case, however, the thermoelectric element is cooled via the heat sink, so that only a small difference occurs between a heated side of the thermoelectric element which is in contact with the CPU and a cooled side thereof which is in contact with the heat sink. Accordingly, only a small electromotive force is obtained through heat generation, and the extent to which this power is reused within the equipment is limited. As a result, this structure is still disadvantageous in the power generation efficiency and the reuse of power.
In view of the above described points, it is an object of the present invention to provide a power generating mechanism that efficiently obtains electric energy using thermal energy from a heat generating component provided in electronic equipment. It is another object to provide a computer apparatus and electronic equipment that can use energy more efficiently by reusing electric energy generated by the power generating mechanism.
To attain the above objects, according to one aspect of the present invention, there is provided a power generating mechanism for electronic equipment having a heat generating component inside, the mechanism comprising a diffusion member kept in contact with the heat generating component to diffuse heat generated by the heat generating component, a thermoelectric conversion module having one side kept in contact with the diffusion member, and a cooling device for cooling the other side of the thermoelectric conversion module.
In the power generating mechanism configured as described above, the diffusion member, formed of a high-heat-conductivity material such as aluminum, is in contact with the heat generating component provided in the electronic equipment, thereby diffusing heat generated by the heat generating component to improve the effect of cooling components.
The thermoelectric conversion module has the one side kept in contact with the diffusion member so as to be heated using heat emitted from the diffusion member. In addition, the other side of the thermoelectric conversion module is cooled by the cooling device.
Thus, a large difference in temperature (a difference in thermal energy) occurs between the opposite sides of the thermoelectric conversion module to increase an electromotive force (electric energy) generated by the thermoelectric conversion module. Additionally, since the thermoelectric conversion module is heated via the diffusion module, excess emitted heat (loss energy) can be absorbed without preventing the heat generating component from being cooled, thereby enabling efficient power generation (energy conversion).
Electronic equipment that already includes the diffusion member or cooling device to cool the heat generating component is preferred because this existing diffusion member or cooling device can be used for the above described effect. In addition, the diffusion member may comprise a heat sink that is shaped like a plate or has a plurality of diffusion fins, and the heat generating component may comprise a semiconductor device for actuating the electronic equipment or a heat generating component on an electric circuit (a transformer or a coil).
The thermoelectric conversion module may be configured by generating electricity using a difference in temperature between one side and the other side thereof, and may comprise a module for activating movement of electrons via dynamic energy or chemical reaction resulting from thermal energy to thereby generate electric energy (generate power).
The thermoelectric conversion module and the heat generating component may be located substantially symmetrically with respect to the diffusion member. If the thermoelectric conversion module and the heat generating component are located substantially symmetrically with respect to the diffusion member, that is, the thermoelectric conversion module is located close to the heat generating component, the one side of the thermoelectric conversion module becomes hotter.
Alternatively, according to another aspect of the present invention, there is provided a power generating mechanism for electronic equipment having a heat generating component inside, the structure comprising a duct having an outside surface kept in contact with the heat generating component to diffuse heat generated by the heat generating component, a thermoelectric conversion module located inside the duct and having one side kept in contact with an inside surface of the duct, and a fan for ventilating an interior of the duct to cool the other side of the thermoelectric conversion module.
In this power generating mechanism, the heat generating component provided in the electronic equipment is in contact with the outside surface of the duct formed of a high-heat-conductivity material such as aluminum, so that the thermoelectric conversion module, located inside the duct in such a manner that the one side thereof is in contact with the inside surface of the duct, has the other side cooled by the fan for ventilating the interior of the duct.
Thus, the thermoelectric conversion module has the one side heated by heat emitted from the duct and the other side directly cooled by means of ventilation by the fan, so that a large difference in temperature occurs between the opposite sides of the thermoelectric conversion module to increase an electromotive force generated by the thermoelectric conversion module.
Since this thermoelectric conversion module is also heated via the duct, power can be efficiently generated using heat while absorbing excess emitted heat without reducing the effect of cooling the heat generating component.
Since this thermoelectric conversion module and the heat generating component are also located substantially symmetrically with respect to the portion of the thermoelectric conversion module which is in contact with the duct, the one side of the thermoelectric conversion module becomes hotter.
According to an alternative aspect of the present invention, there is provided a power generating mechanism for electronic equipment having an internal structural member with a heat generating component disposed near the structural member, the mechanism comprising a thermoelectric conversion module having one side kept in contact with the heat generating component and the other side kept in contact with the structural member.
In this power generating mechanism, the thermoelectric conversion module has the one side kept in contact with the heat generating component, while having the other side kept in contact with a chassis or the like formed of a high-heat-conductivity material such as aluminum to facilitate cooling. This configuration can cause a large difference in temperature between the opposite surfaces of the thermoelectric conversion module to provide a large electromotive force. In addition, since the above described cooling device or fan is not used, power consumption can be reduced, and since the diffusion member or duct is not required, an increase in costs is prevented.
Where the power generating mechanism is employed in the main body of a computer apparatus or the like comprising a keyboard unit disposed in the main body, the heat generating component may be a heat generating element that is related to the CPU (for example, CPU controller) or that is a component. The structural member may be a keyboard support plate or the like for supporting the keyboard unit.
Alternatively, according to a further aspect of the present invention, there is provided a power generating mechanism for electronic equipment having an internal heat generating component, the mechanism comprising a heat pipe having one end in contact with the heat generating component to transmit heat generated thereby, a thermoelectric conversion module having one side kept in contact with the other side of the heat pipe and a cooling device for cooling the other side of the thermoelectric conversion module.
This power generating mechanism uses the heat pipe to improve the effect of cooling the heat generating component, and the heat pipe has the one end kept directly or indirectly in contact with the heat generating component to transmit much of loss heat from the heat generating component to the heat pipe.
The thermoelectric conversion module in contact with the other end of the heat pipe has the one side heated by means of conduction heat from the heat pipe and the other side cooled by the cooling device.
Consequently, the thermoelectric conversion module heated via the heat pipe can also efficiently generate power using heat based on the large difference in temperature between the opposite sides thereof and without preventing the heat generating component from being cooled.
Alternatively, according to one aspect of the present invention, there is provided a power generating mechanism for electronic equipment having a heat generating component inside, the mechanism comprising a duct having an outside surface kept in contact with the heat generating component to diffuse heat generated by the heat generating component, a heat pipe having one end connected to a neighborhood of the portion of the duct which is in contact with the heat generating component, to transmit heat generated by the heat generating component, a thermoelectric conversion module having one side kept in contact with the other end of the heat pipe and the other side kept in contact with a diffusion section of the duct, and a fan for ventilating an interior of the duct to cool the diffusion section.
In this power generating mechanism, the duct has its outside surface kept in contact with the heat generating component and has the one end of the heat pipe connected to the neighborhood of the portion of the duct which is in contact with the heat generating component, to transmit heat generated by the heat generating component.
The thermoelectric conversion module has the one side kept in contact with the other end of the heat pipe and the other side kept in contact with the diffusion section of the duct cooled by the fan, thereby improving the cooling effect on the other side to provide a large electromotive force.
In addition, the duct and heat pipe and the fan cooperate in providing a higher diffusion effect, thereby preventing the cooling effect on the heat generating component from being adversely affected.
Alternatively, the other end of the heat pipe, with which the thermoelectric conversion module is kept in contact, may be shaped like a substantially rectangular pipe. This configuration facilitates mounting of the thermoelectric conversion module. It also has a larger surface area than pipes with a circular cross section or the like, thereby enabling more thermoelectric conversion modules to be mounted.
Alternatively, the thermoelectric conversion module may be a thermoelectric element module using the Seebeck effect. This thermoelectric element module is obtained by arranging and assembling a plurality of semiconductor devices together as a module, thereby enabling the shape of the module to be changed depending on a mounting site. Furthermore, this module can be configured to be small and light and is thus preferably employed in portable equipment.
In addition, in a computer apparatus with the above described power generating mechanism, an electromotive force generated by the thermoelectric conversion module may be used as power for driving one or more designated components of the apparatus. Accordingly, the computer apparatus has an improved energy efficiency.
The designated component(s) may be a drive section such as the above described fan, an illumination section such as LEDs, as well as other logic and subsystems.
Alternatively, this computer apparatus may comprise a power source switching module for switching between the electromotive force generated by the thermoelectric conversion module and power supplied by a main power to drive the designated component(s), depending on the level of the electromotive force from the thermoelectric conversion module.
When the electromotive force from the thermoelectric conversion module becomes lower than a preset threshold, this power source switching module switches the power source so that main power can drive each designated component. As a result, each designated component or the entire computer apparatus can be actuated in a stable way.
Alternatively, according to one aspect of electronic equipment with the above described power generating mechanism, an electromotive force generated by the thermoelectric conversion module may be used as power for driving designated components(s) of the equipment. Accordingly, the electronic equipment has an improved energy efficiency.
Alternatively, this electronic equipment may comprise a power source switching module for switching between the electromotive force generated by the thermoelectric conversion module and power supplied by a main power to drive each designated component, depending on the level of the electromotive force from the thermoelectric conversion module.
Again, when the electromotive force from the thermoelectric conversion module becomes lower than a preset threshold, the power source switching module switches the power source so that a main power can drive each component. As a result, the entire equipment can be operated in a stable manner.
Embodiments of the present invention will be described below with reference to the drawings.